The kidney, one of the most injured organs in critically ill patients, is faced with unique challenges for molecular oxygen regulation. Recent research activities in the pathophysiological mechanism of ... [more ▼]

The kidney, one of the most injured organs in critically ill patients, is faced with unique challenges for molecular oxygen regulation. Recent research activities in the pathophysiological mechanism of acute renal injury (ARI) emphasize the central role of hemodynamic and inflammatory events in septic shock. More particularly, two mechanisms have been postulated to explain the inability of the injured kidney to extract oxygen: tissue hypoxia and cellular energetic metabolism dysfunction. The present investigation was carried out to characterize the effects of bacterial endotoxin on the oxygen consumption of human tubular proximal cell line (PTC) by using the very sensitive electron spin resonance oximetry method. Oxygen consumption was shown to decrease quite markedly in cells treated with lipopolysaccharide (LPS) from 16.52 ± 2.51 (n=6) in the control group to: 12.94 ± 2.62 (n=3) in the short incubation time group (6h) and 10.86 ± 2.20 (n=3) in the long incubation time group (18h). This decrease in oxygen consumption in renal cells after LPS challenge may be in relation with a metabolic down-regulation. Renal energetic are deranged in sepsis not just because O2 delivery is impaired but perhaps also because the ability of cells to utilize available O2 is compromised. [less ▲]

in Biochemical and Biophysical Research Communications (2012), 423(2), 350-354

To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal ... [more ▼]

To study the mechanism of oxygen regulation in inflammation-induced acute kidney injury, we investigate the effects of a bacterial endotoxin (lipopolysaccharide, LPS) on the basal respiration of proximal tubular epithelial cells (HK-2) both by high-resolution respirometry and electron spin resonance spectroscopy. These two complementary methods have shown that HK-2 cells exhibit a decreased oxygen consumption rate when treated with LPS. Surprisingly, this cellular respiration alteration persists even after the stress factor was removed. We suggested that this irreversible decrease in renal oxygen consumption after LPS challenge is related to a pathologic metabolic down-regulation such as a lack of oxygen utilization by cells. [less ▲]

The lungs of 13 healthy Landrace piglets were isolated, perfused and maintained in an isogravimetric state under zone III conditions. By applying vascular occlusion methods, the total blood flow ... [more ▼]

The lungs of 13 healthy Landrace piglets were isolated, perfused and maintained in an isogravimetric state under zone III conditions. By applying vascular occlusion methods, the total blood flow resistance (Rt) was partitioned into four components: arterial (Ra), pre- (Ra') and post-capillary (Rv'), and venous (Rv). The capillary filtration coefficient (Kfc) was evaluated using a gravimetric technique. A bolus of 55 micrograms of Escherichia coli endotoxins (LPS) per 100 g of lung was injected into the arterial reservoir of eight lungs, followed by an infusion of LPS at a rate of 55 micrograms per 100 g of lung per hour for 180 min. A bolus of theophylline (85 mg per 100 g of lung weight) was injected into the arterial reservoir after the last determination of the Kfc value. All the parameters were evaluated again when the lungs reached a new steady state. Endotoxin induced a significant increase in Rt from 54.7 +/- 7.0 at zero time to 184.7 +/- 44.2 cmH2O min L-1 (100 g)-1 180 minutes later, which can be ascribed to the increase in Ra' and Rv'. These haemodynamic modifications were related to the increases in the arterial pressure and in the pressure at the distal end of the arterial segment and to the decreases in the pressure at the proximal end of the venous segment and in the blood flow. The capillary pressure and the lung weight remained unchanged. Endotoxin infusion induced an increase in the Kfc value from 0.208 +/- 0.011 (at t = 0) to 0.391 +/- 0.034 ml min-1 (cmH2O)-1 (100 g)-1 (at t = 180). Administration of theophylline significantly reduced Rt,Ra,Ra' and Rv' towards or under the baseline values and also induced a significant increase in the lung weight and in the Kfc value. It was concluded that the endotoxin-induced increase in the total blood flow resistance can be ascribed to a vasospasm occurring at the level of the pre- and post-capillary small vessels and that changes in the permeability of the endothelium greatly contribute to the development of the pulmonary oedema observed in endotoxaemic pigs [less ▲]

In the trend of the endovascular revolution for occlusive arterial disease, management of aneurysmal disease has known an analogous change in the nineties. Elective endo-aneurysmal stentgrafting (EVAR or ... [more ▼]

In the trend of the endovascular revolution for occlusive arterial disease, management of aneurysmal disease has known an analogous change in the nineties. Elective endo-aneurysmal stentgrafting (EVAR or endovascular aneurysm repair) is nowadays of widespread application in contemporary practice all over the world, sometimes by over-enthusiast proponents. There is a burden of recent publications on that topic. Critical analysis of relevant data reveal compelling evidence that elective EVAR is a safe procedure with a threefold reduced 30-day morbidity-mortality, when compared to conventional open aneurysm repair. EVAR also deemed efficace in terms of AAA rupture prevention. At the other hand, mid-term follow-up revealed that EVAR does not endure at the long-term in any late survival benefit, compared to open AAA repair. The major concern and drawback of EVAR is its higher cost and the need for indefinite, life-long surveillance, with a 20% reintervention rate (almost catheter-based endovascularly) at 5-year follow-up. In this review-paper, short-term gains of EVAR are balanced against the inherent disadvantages and long-term losses. According best available evidence, EVAR should not longer be the first choice for high-risk patients, judged unfit for open aneurysm repair. There also exist doubt on the use of EVAR in young fit patients with an anticipated long life expectancy. In approximately half of the AAA patients, EVAR can be considered as the appropriate treatment option. [less ▲]

Penetrating injuries of the subclavian artery are associated with a high morbidity and mortality rate. Endovascular treatment with covered stents (stent grafts) has emerged as an effective alternative to ... [more ▼]

Penetrating injuries of the subclavian artery are associated with a high morbidity and mortality rate. Endovascular treatment with covered stents (stent grafts) has emerged as an effective alternative to surgery, but this new technique is not exempt from complications. We report the case of a male gunshot victim, treated by a covered stent for haemorrhagic shock due to partial subclavian rupture. [less ▲]

We describe the placement of an endovascular stent-graft in a patient with mycotic aneurysm of the descending thoracic aorta caused by Salmonella. Endovascular grafting combined with antibiotic therapy in ... [more ▼]

We describe the placement of an endovascular stent-graft in a patient with mycotic aneurysm of the descending thoracic aorta caused by Salmonella. Endovascular grafting combined with antibiotic therapy in thoracic mycotic aneurysms might represent an alternative to conventional surgery in patients with high operative risk. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

The effects of a single oral dose of 40 mg propranolol on endurance time and on the maximum oxygen consumption were studied in eight healthy young men. They were running on a motor-driven treadmill (work ... [more ▼]

The effects of a single oral dose of 40 mg propranolol on endurance time and on the maximum oxygen consumption were studied in eight healthy young men. They were running on a motor-driven treadmill (work rate from 80 to 150% VO2 max. The VO2 max and endurance time were decreased to an average of 10 and 30% of controls respectively. The relationship between the endurance time and the relative work load (VO2/VO2 max) remained unchanged after beta-adrenoceptor blockade. The reduction of the endurance time following beta-adrenoceptor blockade is a consequence of the reduction of the VO2 max. [less ▲]

Asteroseismology is one of the major important science topics in astrophysics in the coming decade. Several recent breakthroughs have indeed been made in Europe in this field. The observational data will ... [more ▼]

Asteroseismology is one of the major important science topics in astrophysics in the coming decade. Several recent breakthroughs have indeed been made in Europe in this field. The observational data will improve significantly in the near future, as upgraded ground-based instruments are being built and two European asteroseismic space missions are planned for launch between 2005 and 2008. They will provide us for the first time with ultra-high-accuracy, high-temporal resoluton data from space for stars other than the Sun. A successful asteroseismic study involves many different steps, from state-of-the-art raw data treatment to theoretical physical modelling of the oscillation frequencies. Our network is set up to meet the needs of combining and exchanging the different expertises of the participating institutes, of training PhD students and of both training and exchanging post-doctoral researchers. This will guarantee the most fruitful and efficient exploitation of the very substantial investments that are being made in Europe in future observations of stellar oscillations, strengthening Europe's leading position in this research field. Also, it will be a test-bed for the development of efficient procedures for collaboration across the internet, involving a vast range of procedures and skills, as well as extensive common use of a broad variety of data. Furthermore, procedures will be incorporated for the joint training of students, which is an essential part of our project. [less ▲]

The mivazerol and three of its methylated derivatives are studied at the ab initio SCF level within the MINI-1 and 6-31G basis sets. This study aimed at determining some probable conformations, either ... [more ▼]

The mivazerol and three of its methylated derivatives are studied at the ab initio SCF level within the MINI-1 and 6-31G basis sets. This study aimed at determining some probable conformations, either neutral or protonated, that could interact with the alpha 2 adrenoceptors. The solvent effect was also studied within the Onsager's solvent model at the two dielectric constant (epsilon) values of 4 and 80. The interaction with the environment (either solvent or receptor) is schematically studied by positioning either two water molecules or one formamide or/and one formic add near the amide and the imidazole for few isomers. The medium polarization, through epsilon, and the solvation effect, through the interaction with the solvent molecules or the receptor side chains, stabilize the same isomers. Post-SCF calculations are performed at the CISD level, the first excited singlet and triplet states energies are determined, and the question of the wave-function stability is addressed. The results indicate the probability of a spin-orbit coupling with the first excited triplet state, thus opening the question of such a possibility within an enzyme active site. (C) 1996 John Wiley & Sons, Inc. [less ▲]

This paper describes the experiment that was carried out at the Thermodynamics Laboratory of the University of Liège (Belgium) to study the impact of the use of vegetable oil as a substitute for light oil ... [more ▼]

This paper describes the experiment that was carried out at the Thermodynamics Laboratory of the University of Liège (Belgium) to study the impact of the use of vegetable oil as a substitute for light oil on the short-term performance of Diesel engines for cars. The vegetable oil selected is derived directly from rapeseed without any refinement processes. Five tests were carried out, going from 0% rapeseed oil blended in conventional Diesel fuel (reference fuel) up to 100% rapeseed oil. For each test, the whole operating range of the engine was swept and the fuel consumption and exhaust emissions measured simultaneously. The study concludes that the engine used during the research can be run with 100% unrefined rapeseed oil. Nevertheless, using 100% oil is not considered as a valid large scale solution. However, using a smaller percentage of rapeseed oil gives promising results in terms of reduction of CO2 emission as well as reduction of the opacity of the exhaust gases. [less ▲]

In order to assess the performances of the domestic heating boilers with a CE mark, a wood pellets fired condensing boiler has been purchased and installed in the Laboratory for tests. The objective of ... [more ▼]

In order to assess the performances of the domestic heating boilers with a CE mark, a wood pellets fired condensing boiler has been purchased and installed in the Laboratory for tests. The objective of the study was not only to check the announced performances, but mainly to investigate the influence of the different parameters affecting the functioning of the boiler, the thermal efficiency and the pollutants (NOx and CO) emission being aimed at. Tests have been performed to study the influence of the cycling frequency of the burner functioning, the overall excess air, the return water temperature, and the output power of the boiler. As announced by the manufacturer, the tested boiler fulfils the requirements of the Blue Angel Label, but the recommended value for the excess air (1.2) can be reduced to a value of about 0.4 without excessive emissions of CO. The boiler could perform better if the ON period of the cycle of the burner is increased even better if the OFF period is suppressed. The NOx are mainly formed from the nitrogen content of the pellets and their emissions can only be reduced by a lower nitrogen content of the pellets than the limit stated in the standard. Random peaks observed in the evolution of CO, the boiler being operating in steady state regime, are attributed to the combustion process of pellets which is a non-continuous process by nature. [less ▲]

We report numerical investigations for the compaction dynamics of dense granular assemblies. The studies are based on the non-smooth contact dynamics model. Our work suggests that the dimensionless ... [more ▼]

We report numerical investigations for the compaction dynamics of dense granular assemblies. The studies are based on the non-smooth contact dynamics model. Our work suggests that the dimensionless acceleration parameter Gamma, used by a large majortiy of authors, is not appropriate for rescaling the data. We prove that the dimensionless energy Xi, injected in the granular system at lift-off, is more appropriate and leads to robust interpretations of the compaction dynamics. Indeed, the injected energy allows to pass energy barriers that separate local equilibrium states. Using the Eyring picture of relaxation dynamic, we show that the consideration of Xi leads to a new law for compaction. [less ▲]

The non-radial oscillations discovered by CoRoT (see e.g. de Ridder et al. (2009)) and by Kepler(see e.g. Bedding et al. (2010)) in thousands of red giants constitute a wonderful mine of information to determine their global characteristics and probe their internal structure. A. Miglio and J. Montalbán have presented in detail in this conference the seismic structure of red giants, the information hold by their oscillation frequencies, and how it can be used. An adiabatic analysis of the oscillations was sufficient at this level as the frequencies are mainly determined by the deep layers were the oscillatons are quasi-adiabatic. We consider here energetic aspects of non-radial oscillations in red-giants. Non-adiabatic models of solar-like oscillations are required to determine the theoretical amplitude and lifetimes of the modes. These parameters allow us to determine how power spectra are expected to look like, depending on the structure of the red giant. Comparison with the observed measures gives thus additional constraints on the models. [less ▲]

Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by ... [more ▼]

Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies principally on a range of plastid-localized ATP generating processes. Here we show that diatoms regulate ATP/NADPH through extensive energetic exchanges between plastids and mitochondria. This interaction comprises the re-routing of reducing power generated in the plastid towards mitochondria and the import of mitochondrial ATP into the plastid, and is mandatory for optimized carbon fixation and growth. We propose that the process may have contributed to the ecological success of diatoms in the ocean. [less ▲]